Siemens SINUMERIK 840D Function Manual page 801

● Mechanical switchover of the gear stage on the machine.
No oscillation movement is required from the drive.
NC/PLC IS:
DB31, ... DBX18.5 (oscillation enable)
and
DB31, ... DBX18.4 (oscillation via PLC)
should not be set.
In principle, oscillation movement is still possible at this point.
● Writing of NC/PLC IS:
DB31, ... DBX16.0-16.2 (actual gear stage A to C)
by the PLC.
● After signal:
DB31, ... DBX16.3 (gear stage changed),
the last movement to be active is continued, if available.
For indirect encoders (motor encoders), the referencing status is cleared:
DB31, ... DBX60.4/5 = 0.
The spindle is in speed control mode and NC/PLC IS:
DB31, ... DBX84.7 (open-loop control mode)
is output.
Axes and spindles
Function Manual, 06/2019, A5E47437747B AA
S1: Spindles
18.4 Configurable gear adaptations
801